Component mounting apparatus employing temperature maintenance of positioning accuracy

ABSTRACT

A component mounting method and a component mounting apparatus for picking up an electronic component, positioning the electronic component on a circuit substrate and mounting the electronic component to the circuit substrate are adapted to perform an idling operation during a pause of component mounting operation, thereby eliminating any degradation of the component mounting accuracy due to temperature changes.

This is a divisional application of application Ser. No. 10/007,821,filed Dec. 5, 2001, Now U.S. Pat. No. 6,920,687 the disclosure of whichis incorporated herein by reference and which relates to subject mattercontained in priority Japanese Patent Application No. 2000-371274, filedon Dec. 6, 2000, the contents of which is herein expressly incorporatedby reference in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a component mounting method and acomponent mounting apparatus for mounting electronic components andother components on a circuit substrate.

2. Description of Related Art

A conventional electronic component mounting apparatus shown in FIG. 10includes an XY robot 1 adapted to position a head 3 having a nozzle 2.The XY robot 1 includes an X-axis robot 1 a and Y-axis robots 1 b-1 and1 b-2. An electronic component 5 is picked up from a component supplysection 4 by the nozzle 2 and is moved with the head 3 to the mountingposition on the circuit substrate 7 that is secured to an XY table 6.Then, the electronic component 5 is mounted onto the circuit substrate7.

The operation of mounting the electronic component 5 on the circuitsubstrate 7 requires an enhanced degree of precision particularly when anumber of components are to be arranged densely on the circuit substrate7. For instance, if a 0.6 mm long and 0.3 mm wide micro-chip isdisplaced by more than ±25 μm from the right mounting position, stablebonding of an electrode of the chip and a corresponding land of thecircuit substrate can not be achieved. However, the X-axis robot, theY-axis robot, the center position of a camera CCD and various otherparts of the machine frame become displaced due to temperature changescaused by environmental temperature changes, heat generated by a drivemotor and other motors when the machine is made to start operating, andheat generated in sliding areas of the X-axis/Y-axis robots and so on.Consequently, the centers of components are displaced from thepredetermined respective positions, thereby decrease the accuracy ofmounting of the components.

This problem will be described in detail with reference to FIG. 11.

In FIG. 11, the X-axis robot 1 a drives the head 3 along the X-axis byemploying a motor 30, while the Y-axis robots 1 b-1 and 1 b-2 supportthe X-axis robot 1 a at the respective ends thereof and drive the X-axisrobot along the Y-axis (running in a direction perpendicular to thesheet showing FIG. 11). Normally, it is so arranged that one of theopposite ends of the X-axis robot 1 a, e.g., the end where the Y-axisrobot 1 b-1 is located, is rigidly held, while the other end thereof,e.g., the end where the Y-axis robot 1 b-2 is located, is able to slidein the X-direction.

The X-axis robot 1 a receives heat generated by the motor 30, andfrictional heat of the head 3 as well as that of the X-axis robot 1 aitself as it slides on the Y-axis robots 1 b-1 and 1 b-2. The X-axisrobot 1 a expands as the temperature thereof rises. Particularly, theX-axis robot 1 a expands in the X-direction at the side of the Y-axisrobot 1 b-2 by ΔX₁. As a result of the expansion, the head 3 isdisplaced in the X-direction by the amount indicated by a broken line inFIG. 11. Accordingly, the nozzle 2 is displaced in the X-direction byΔX₂.

The Y-axis robots 1 b-1 and 1 b-2 and frames supporting the Y-axisrobots also receive heat and expand in a similar way. Thus, the nozzle 2is displaced by the combined effect of these expansions.

While the displacement of the nozzle 2 may be very small, it will not benegligible when it exceeds the required accuracy of positionalarrangement.

Known electronic component mounting apparatus is normally provided withan automatic calibration feature for preventing degradation in theaccuracy of positional arrangement due to temperature change. With thisfeature, whenever necessary, the electronic component mounting apparatusautomatically carries out a calibrating operation as a function of thetemperature change from a predetermined level or the time elapsed fromthe last calibration. The calibrating operation is carried out byattaching a calibration jig to the nozzle 2, the jig for determining thecenter of the nozzle 2 of the head 3, positioning the jig, picking up animage of the nozzle 2 with a camera, determining a displacement of thecenter of the nozzle 2 in terms of coordinates adopted for positioning,and updating the amount of offset (positional displacement due totemperature changes) relative to the mechanical original point of theapparatus.

However, the amount of offset relative to the mechanical original pointof the apparatus as determined with the calibration jig is the sum ofthe amounts of offset of each of the units (including the head 3, the XYrobots 1, and the camera) due to temperature changes. The amount ofoffset of each unit varies from a time of measurement to another so thaterrors arise. Consequently, the accuracy of positional arrangement ofelectronic component may be degraded even when the units are correctedin accordance with the amount of offset obtained by the calibratingoperation.

Additionally, with the above-described scheme of automatic calibration,the nozzle, the camera and other components need to be subjected to acalibrating operation individually so that the productivity willdeteriorate.

Still additionally, when the apparatus is made to start operating aftera long pause spent for switching to a different type of devices, theamount of offset varies immediately because the temperature change isgoing on in the start-up phase. This means that the amount of offsetobtained by the automatic calibration is reduced useless and the amountof the offset of each of the units needs to be determined anew.

SUMMARY OF THE INVENTION

In the light of the above problems, an object of the present inventionis to provide a component mounting method and a component mountingapparatus that prevents positional displacements of electroniccomponents due to temperature changes and improves the productivitythereof.

According to the invention, there is provided a component mountingmethod and a component mounting apparatus including picking up anelectronic component, positioning the electronic component on a circuitsubstrate, and mounting the electronic component onto the circuitsubstrate, the method and apparatus being adapted to eliminate any fallof the temperature of the apparatus during a pause of component mountingoperation, thereby eliminating any reduction of the component mountingaccuracy due to temperature changes.

Preferably, the apparatus is made to run idle during a pause ofcomponent mounting operation. The idling operation may be carried outduring a standby period of the substrate. Alternatively, it may becarried out when a controller determines that the temperature change ofeach of the units or a suspending time is out of the allowable limitduring a pause of component mounting operation for switching to adifferent type of devices or for a maintenance operation.

While novel features of the invention are set forth in the preceding,the invention, both as to organization and content, can be furtherunderstood and appreciated, along with other objects and featuresthereof, from the following detailed description and examples when takenin conjunction with the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic perspective view of a first embodiment of acomponent mounting apparatus according to the invention, illustratingits configuration;

FIG. 2 is a block diagram according to the embodiment, illustrating thesystem for controlling the apparatus;

FIG. 3 is a schematic illustration of an idling operation according tothe embodiment;

FIG. 4 is a flow chart of the idling operation according to theembodiment;

FIG. 5 is a graph illustrating the relationship between the temperaturechange of the apparatus after starting a component mounting operationand the positional displacements of various units of the apparatus;

FIG. 6 is a graph illustrating the operation of controlling the idlingoperation according to a third embodiment of the invention;

FIG. 7 is a schematic illustration showing arrangement of sensorsaccording to a fourth embodiment of the invention;

FIG. 8 is a schematic illustration of an image displayed on a screen ofa monitor according to the embodiment, the image for selecting thetemperatures of different units to be maintained by an idling operation;

FIGS. 9A and 9B are schematic illustrations of images displayed on thescreen of the monitor for showing a transition in unit temperatureaccording to the embodiment;

FIG. 10 is a schematic perspective view of a conventional componentmounting apparatus, illustrating its configuration; and

FIG. 11 is a schematic illustration of displacements of a head and an XYrobot of the conventional apparatus due to a temperature change.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Preferred embodiments of the present invention will be hereinafterdescribed with reference to FIGS. 1 through 9B.

First Embodiment

A first embodiment will be described with reference to FIGS. 1 to 5.FIG. 1 illustrates the configuration of a component mounting apparatusaccording to the embodiment. As shown in FIG. 1, an XY robot 1 isadapted to position a head 3 having a nozzle 2. The XY robot 1 includesan X-axis robot la for positioning the head 3 in the X-direction andY-axis robots 1 b (1 b-1 and 1 b-2) for positioning the head 3 in theY-direction, and the head 3 includes an H-axis robot 31 (see FIG. 2) forpositioning the nozzle 2 in the Z-direction by moving the nozzlevertically. Reference numeral 4 denotes a component supply section forsupplying an electronic component 5. Reference numeral 6 denotes apositioning table for positioning a circuit substrate 7 in theY-direction. Reference numeral 8 denotes a loader section for receivinga circuit substrate 7 from the preceding process and reference numeral 9denotes an unloader section for holding the circuit substrate 7 mountedwith electronic components in a standby state before it is transferredto the next step. Although not shown, the unloader section 9 is arrangedalong a carrier rail and adapted to convey the circuit substrate 7 byemploying a motor-driven belt. Reference numeral 10 denotes a controllerfor controlling the operation of each of the units including the XYrobot 1, the head 3, the component supply section 4, the positioningtable 6, the loader section 8 and the unloader section 9, and referencenumeral 11 denotes an operating section adapted to be used for theoperation of inputting NC programs. Reference numeral 12 denotes acomponent recognition camera for recognizing the electronic component 5picked up from the component supply section 4 by the nozzle 2 andreference numeral 13 denotes a nozzle station for storing a sparenozzle.

Now, the operation of controlling the component mounting apparatusaccording to the embodiment will be described with reference to FIG. 2.

The X-axis robot 1 a moves the head 3 in the X-direction by rotating aball screw by a motor under control of the controller 10. The Y-axisrobots 1 b-1 and 1 b-2 support the X-axis robot 1 a at the opposite endsthereof and drives it in the Y-direction by rotating respective ballscrews by a motor under control of the controller 10. Thereby, thenozzle 2 of the head 3 is moved on the XY plane until it is placed at adesired position. Alternatively, the X-axis robot 1 a and the Y-axisrobots 1 b-1 and 1 b-2 may be driven by a linear motor.

The H-axis robot 31 moves the nozzle 2 vertically in the Z-directionunder control of the controller 10. An θ-axis robot 32 rotates thenozzle 2 around its axial center under control of the controller 10until the picked up component shows the right mounting angle.

The positioning table 6, the loader section 8 and the unloader section 9are adapted to transfer the circuit substrate 7 by driving the carrierbelt by a corresponding motor under control of the controller 10.

The component supply section 4 supplies electric components sequentiallyby moving at respective pitches a tape holding the components thereon atregular intervals employing a motor under control of the controller 10.

The component recognition camera 12 picks up an image of the componentbeing moved by the head 3 to show the position at which it is held bythe nozzle 2 and its posture under control of the controller 10. Thepicked up image is input to a component recognition processing section35, which processes the input image and detects the displacement of thecenter of the component and that of the nozzle and the angulardisplacement of the component. The controller 10 issues a command to theX-axis robot 1 a, the Y-axis robots 1 b-1 and 1 b-2 and the θ-axis robot32 so as to make the component to be mounted on the circuit substrate atthe right position and at the right angle, using the detected amounts ofdisplacement for correction.

Next, the operation of the component mounting apparatus having theabove-described configuration will be discussed below. The circuitsubstrate 7 is moved from the loader section 8 onto the positioningtable 6 and placed in position. Then, the head 3 is driven to move andmake the nozzle 2 pick up the electronic component 5 from the componentsupply section 4. The head 3 is further driven to move to the mountingposition on the circuit substrate 7 and cause the nozzle 2 to mount theelectronic component 5 held by it on the circuit substrate 7. Thecircuit substrate 7 is then transferred to the next step by the unloadersection 9. All the above operation is carried out under control of theactual operation section 40 in the controller 10.

In the above-described component mounting apparatus, the temperature ofeach of the units rises from the start of the operation. Then, each ofthe units will thermally expand and eventually deflected due to thethermal expansion to consequently displace the nozzle 2. FIG. 5schematically illustrates how the nozzle 2 is displaced. FIG. 5 is agraph illustrating the relationship between the temperature change ofthe XY robot 1 with time after starting a component mounting operationand the positional displacements in the X- and Y-directions with time ofvarious units of the apparatus, including the X-axis robot 1 a, theY-axis robots 1 b and the component recognition camera 12. As shown inFIG. 5, the temperature of the XY robot 1 rises from the start of theoperation and the displacement of the Y-axis robot 1 b increasesaccordingly. However, after the elapse of a certain period of time, boththe temperature and the displacement come to be held to a stabile state.

Consequently, the amount of offset of the nozzle 2 (displacement due totemperature change) is held to a stable level to ensure a high degree ofaccuracy for the mounting operation if the time required for the XYrobot 1 to rise to the stable state from the start of the mountingoperation is shortened and the stable state is maintained during themounting operation.

The component mounting apparatus according to the embodiment operates ina manner as described below to maintain the stable state.

When a next circuit substrate 7 is not found in the loader section 8 orthe next circuit substrate 7 is being transferred from the loadersection 8 onto the positioning table 6, the X-axis robot 1 a and theY-axis robots 1 b of the XY robot 1 and the H-axis robot 31automatically and idly move back and forth between the mechanicaloriginal point and the point at the maximum traveling distance from theoriginal point or a predetermined point. As a result of this idlingoperation, the temperature of each of the related units is maintained tothe stable level for operation to ensure a high degree of accuracy. Theidling operation is controlled by an idling section 41 of the controller10.

The control procedure of the idling operation will be described belowwith reference to the flow chart of FIG. 4. As the controller 10 (theidling section 41) detects that there is a circuit substrate 7 in astandby state (Step #1), it determines if an idling operation isnecessary or not by referring to the time elapsed since the lastoperation of mounting electronic components or the temperature of eachof the related units (including the head 3, the XY robot 1 and thecomponent recognition camera 12) (Step #2). If it is determined that anidling operation is necessary, the controller 10 issues a command forthe idling operation and drives the X-axis and the Y-axis of the XYrobot 1 and the H-axis of the head 3 for the idling operation (Step #3).If, on the other hand, it is determined that no idling operation isnecessary, it switches the control to the actual operation section 40and stands by without any idling operation until a circuit substrate 7is brought in. When a circuit substrate 7 is moved onto the positioningtable 6 while the apparatus is operating idly, it stops the idlingoperation (Step #4) and starts the operation of mounting the electroniccomponent 5 (switches the control to the actual operation section 40)(Step #5). Thus, the mechanical positional accuracy of the head 3 due tothe temperature change of each of the units is minimized.

It may alternatively be so arranged that the idling operation continuesso long as the controller 10 keeps on issuing the command for the idlingoperation on the basis of the standby period, the temperature change ofeach of the units and other factors.

Additionally, it may be so arranged that, if the controller 10determines in Step #4 that the temperature of each of the units and theamount of offset of the nozzle 2 have not been put back to the stablestate at the time when the circuit substrate 7 is brought in, itcontinues the idling operation until the stable state is restored,suspending the transfer of the circuit substrate 7 to give priority tothe mounting accuracy. The operator gives priority to either themounting accuracy or the availability ratio of the apparatus by sosetting the controller 10 by way of the operating section 11.

The traveling distance of each of the robots in the idling operation isdetermined on the basis of the temperature fall of each of the unitsfrom that of the stable state and the time before the start of the nextcomponent mounting operation. It will be appreciated that the timerequired for restoring the stable state is reduced by increasing thetraveling distance and the traveling rate of the movement.

Any method may be used for detecting the temperature of each of theunits. Instead of detecting the temperatures of the units, the amount ofoffset of the nozzle 2 may be monitored and detected.

Second Embodiment

Next, a second embodiment of the component mounting apparatus adapted toperform an idling operation when the normal operation of the apparatusis suspended for switching to a different type of device to be assembledby the embodiment will be described.

An idling operation will be carried out automatically during the periodfor switching to a different type of device to be assembled by theapparatus by defining so at the time of initializing the apparatus. Inaddition, the idling operation will be carried out by the time controlor temperature control feature of the controller 10 whenever the normaloperation of the apparatus is suspended for a predetermined period oftime or the temperature of the apparatus changes beyond a predeterminedlimit.

According to the embodiment, the change in the amount of offset from themechanical original point of the apparatus is minimized when theapparatus is at rest.

Instead of carrying out an automatic idling operation, the idlingoperation may be started and stopped by turning on and off a switch foridling operations of the operating section 11.

An additional switch may be provided so as to select a manual idlingoperation mode where an idling operation is started and stopped byoperating the above switch or an automatic idling operation mode wherethe controller 10 starts and stops an idling operation according to itsown judgment.

Third Embodiment

A third embodiment of the component mounting apparatus according to theinvention will be described with reference to FIGS. 5 and 6. Thisembodiment is adapted to automatically start an idling operation on thebasis of the correlation of the time elapsed since the start ofoperation of the apparatus, the temperature and the mounting accuracy.

Referring firstly to FIG. 5, as the apparatus starts operating, thetemperature rises. Two hours after the start, the temperature risebecomes saturated and the displacement of any of the units isstabilized. As shown in FIG. 6, an allowable temperature zone A wherethe displacement of any of the units does not go beyond the mountingaccuracy limit is defined for the apparatus. As the temperature of theapparatus goes into the allowable temperature zone A, the idlingoperation of the apparatus is terminated to start an actual mountingoperation.

If the apparatus stops the mounting operation because the next circuitsubstrate is not in position or the apparatus has to switch to adifferent type of devices, the controller 10 determines if the apparatusneeds to start an idling operation by referring to the allowabletemperature zone A and the current temperature on the basis of thecorrelation of the duration of idling and the temperature rise stored inthe data base.

It may be so arranged that, once an idling operation starts, thecontroller 10 measures the duration of the operation and also constantlyobserves the temperature of each of the units and the apparatus stopsthe idling operation when the controller 10 determines that thetemperature of the apparatus has gone into the allowable temperaturezone A.

Fourth Embodiment

A fourth embodiment of the invention will be described with reference toFIGS. 7 and 8. Certain units of this apparatus are provided withrespective temperature sensors and the apparatus is so adapted that ifit starts an idling operation or not is determined on the basis of thetemperature of each of the units.

As shown in FIG. 7, the X-axis robot 1 a and the Y-axis robots 1 b ofthe XY robot 1, the head 3, the component recognition camera 12 and someother units are provided with respective temperature sensors 14 and theoperating section 11 is so adapted that the operator sets the referencetemperature of each of the units to be referred to for starting anidling operation by way of the operating screen of the operating section11 as shown in FIG. 8. If the temperature of any of the units asdetected by the corresponding sensor falls below the referencetemperature and hence the mounting accuracy of the apparatus becomes nolonger acceptable, the controller 10 automatically starts an idlingoperation. In FIG. 7, reference numeral 12 a denotes a support of thecomponent recognition camera 12 and reference numeral 13 denotes thenozzle station.

While an idling operation is started when the temperature of any of theunits falls the corresponding reference temperature in the abovedescription, it may alternatively be so arranged that each of thecertain units is further provided with a heater and the temperature ofeach of the units is maintained to a certain level by the heater afterthe end of every actual mounting operation.

The temperature of each of the units as detected by the correspondingsensor may be displayed on the operating screen or the monitor screen ofthe operating section 11 to show the transition with time of thetemperature in a manner as shown in FIG. 9A. Additionally, it may be soarranged that, when the temperature of any of the units falls below theallowable temperature zone A, a warning message is displayed on thescreen as shown in FIG. 9B to prompt the operator for an idlingoperation. Then, the operator will determine if the apparatus needs anidling operation or not.

Alternatively, it may be so arranged that the controller 10 determinesif the apparatus needs an idling operation or not as it monitors thetemperature of each of the units.

Data showing the change with time of the temperature of each of theunits may be stored and accumulated. When the mounting accuracy of theapparatus falls, they may be analyzed to detect the cause of thedegraded mounting accuracy.

As described above, with a component mounting method and a componentmounting apparatus according to the invention, the degradation of thecomponent mounting accuracy due to temperature change of any of theunits of the apparatus is avoided by an automatic idling operationand/or the use of heaters. The frequency of calibrating operation istherefore reduced. Consequently, the component mounting accuracy isimproved remarkably along with improvement of the productivity of theapparatus.

Although the present invention has been fully described in connectionwith the preferred embodiment thereof, it is to be noted that variouschanges and modifications apparent to those skilled in the art are to beunderstood as included within the scope of the present invention asdefined by the appended claims unless they depart therefrom.

1. A component mounting apparatus comprising: a component supply sectionfor supplying components; a mounting head section for picking up acomponent from the component supply section and mounting the componentonto a circuit substrate, said mounting head section including an x-yrobot and a mounting head positioned by the x-y robot; and a controllerfor controlling the component supply section and the mounting head, thecontroller including: a pause detection section for detecting a pause ofa component mounting operation during which the mounting section headneed not be operated to mount components; an idling determinationsection for determining whether an idling operation is required based ondetection of the pause; and an idling section for controlling theapparatus so as to perform an idling operation during the pause of thecomponent mounting operation to prevent a fall of a temperature of thecomponent mounting apparatus during the pause of the component mountingoperation such as to reduce degradation of a component mounting accuracydue to temperature changes, said idling operation being performed inresponse to a determination by the idling determination section that theidling operation is required, and said idling operation includingdriving the x-y robot to move without effecting mounting of a component.2. The component mounting apparatus according to claim 1, furthercomprising a temperature sensor provided in at least one section of thecomponent mounting apparatus, wherein the idling section is adapted tostart an idling operation based on the temperature detected by thesensor based on the idling determination section determining whether toeffect said idling operation based further upon the temperaturedetected.
 3. The component mounting apparatus according to claim 2,wherein the idling determination section determines if a temperaturechange of the at least one section of the apparatus is out of anallowable limit during the pause of component mounting operation, and isadapted to make the idling section perform the idling operation when thetemperature change is out of the allowable limit.
 4. The componentmounting apparatus according to claim 3, wherein the idling section isadapted to continue the idling operation and block a next circuitsubstrate being brought in when it is determined that the temperaturechange of the at least one section is out of the allowable limit.
 5. Thecomponent mounting apparatus according to claim 4, further comprising aheater provided with a section of the component mounting apparatus,wherein the idling section further controls the temperature of thesection using the heater during the pause of the component mountingoperation.
 6. The component mounting apparatus according to claim 5,wherein the idling section effects the idling operation during waitingfor a next circuit substrate.
 7. The component mounting apparatusaccording to claim 3, further comprising a heater provided with asection of the component mounting apparatus, wherein the idling sectionfurther controls the temperature of the section using the heater duringthe pause of the component mounting operation.
 8. The component mountingapparatus according to claim 7, wherein the idling section effects theidling operation during waiting for a next circuit substrate.
 9. Thecomponent mounting apparatus according to claim 2, further comprising aheater provided with a section of the component mounting apparatus,wherein the idling section further controls the temperature of thesection using the heater during the pause of the component mountingoperation.
 10. The component mounting apparatus according to claim 9,wherein the idling section effects the idling operation during waitingfor a next circuit substrate.
 11. The component mounting apparatusaccording to claim 1, further comprising a heater provided with asection of the component mounting apparatus, wherein the idling sectionfurther controls the temperature of the section using the heater duringthe pause of the component mounting operation.
 12. The componentmounting apparatus according to claim 1, wherein the idlingdetermination section determines if a suspending period is out of anallowable limit during the pause of the component mounting operation,and is adapted to make the apparatus perform the idling operation whenthe suspending period is out of the allowable limit.
 13. The componentmounting apparatus according to claim 12, further comprising atemperature sensor provided in at least one section of the componentmounting apparatus, wherein the idling section is adapted to start anidling operation based on the temperature detected by the sensor basedon the idling determination section determining whether to effect saididling operation based further upon the temperature detected.
 14. Thecomponent mounting apparatus according to claim 13, wherein the idlingdetermination section determines if a temperature change of the at leastone section of the apparatus is out of an allowable limit during thepause of component mounting operation, and is adapted to make the idlingsection perform the idling operation when the temperature change is outof the allowable limit.
 15. The component mounting apparatus accordingto claim 14, wherein the idling section is adapted to continue theidling operation and block a next circuit substrate being brought inwhen it is determined that the temperature change of the at least onesection is out of the allowable limit.
 16. The component mountingapparatus according to claim 15, further comprising a heater providedwith a section of the component mounting apparatus, wherein the idlingsection further controls the temperature of the section using the heaterduring the pause of the component mounting operation.
 17. The componentmounting apparatus according to claim 13, further comprising a displayscreen for displaying whether the temperature of the at least onesection is within the allowable limit.
 18. The component mountingapparatus according to claim 13, wherein the idling section effects theidling operation during waiting for a next circuit substrate.
 19. Thecomponent mounting apparatus according to claim 1, further comprising anoperating section for operating the apparatus for mounting a component,wherein the idling section is adapted to start the idling operation whena switch of the operating section is turned on.
 20. The componentmounting apparatus according to claim 1, wherein the idling sectioneffects the idling operation during waiting for a next circuitsubstrate.